I had periods firstly from 30april to 4 may and den again frm 27 may to 31 may in june no periods?

Now whole june has ended till nt having my periods I had unprotected sex with my bf on 13 june but checked frm pregnancy kit it shown negative result want to know the reason why am nt having my periods

You are really not all that late-just a few days. It may yet show up or it may have been possible that a pregnancy test was too early. If you are not wanting to become pregnant, you need to use some reliable method of birth control because sooner or later, you will become pregnant having unprotected sex.